Tubing caliper



Aug- 30, 1960 A. H. BRANDON. 2,950,538

TUBING CALIPER Filed April 5, 1958 3 Sheets-Sheet l BY y AUS'- 30, 1960A. H. BRANDON 2,950,538

TUBING CALIPER Filed April 3, 1958 3 Sheets-Sheet 2 ,QQ/HU@ fr. BQNO/V,

INVENTOR.

BY l

Aug. 30, 1960 A. H. BRANDON 2,950,538

TUBING CALIPER Filed April 3, 1958 3 Sheets-Sheet 3 @eff/0 h. HQQ/VOMINV ENTOR.

United States Patent TUBING CALIPER Arthur H. Brandon, 1450 RamilloAve., Long Beach 15, Calif.

Filed Apr. '3, 1958, Ser. No. 726,152

'1 Claim. (Cl. 33-178) This invention -relates to improvements in tubingcalipers primarily designed for the piupose of determining whether wallsof tubing in a well have corroded or have been worn and to what extent.

A primary object of the present invention is to provide an improvedtubing caliper having a plurality of radially arranged fingersyswingably mounted on a central supporting structure and urged outwardlyinto engagement with the walls of a tubing, and to provide an improvedconstruction for transmitting the movements of the feeler fingers sothat the extent to which the tubing walls have corroded or worn away canbe accurately ascertained.

Another object of the invention is to provide a tubing caliper wherein asimple but highly efficient means is provided for pivotally mounting thefeeler fingers and their movement transmitting bellcranks or levers onthe central Supporting structure.

Another object of the invention is to provide a novel, simple mechanismfor electrically transmitting in an intelligible manner the movements ofthe feeler fingers to the surface, and to provide a construction bywhich the same can be very accurately adjusted.

With the foregoing and other objects in view, which will be mademanifest in the following detailed description and specifically pointedout in the appended claim, reference is had to the accompanying drawingsfor an illustrative embodiment of the invention, wherein:

Figure 1 is a sectional View through a tubing illustrating the centralportion of the tubing caliper embodying the present invention asdisposed therein;

Fig. 2A is a sectional view through the upper portion of the part of theapparatus illustrated in Fig. 1, illustrating the apparatus in thatposition assumed when the fingers are in an unworn or uncorroded portionof tubing as illustrated in Fig. 2B;

Fig. 2B is a sectional view of the lower portion of that part of theapparatus illustrated in Fig. l;

Fig. 3A `and Fig. 3B are views similar to Figs. 2A and 2B, respectively,but illustrating the apparatus in that position assumed when one or moreof the feeler lingers have encountered a recess in the tubing wall thatmay have been occasioned either by corrosion or tubing wear;

Figs. 4 and 5 are horizontal sections, respectively, taken upon thelines 4-4 and 5 5 in Fig. 2B in the direction indicated; and

Fig. 6 is a wiring diagram.

Referring to the accompanying drawings wherein similar referencecharacters designate similar parts throughout, the improved tubingcaliper comprises a central bar or mandrel 10 adapted to be lowered suchas by a conductor cable in a tubing T that is to be tested. At theA topand bottom of that portion of the apparatus illustrated in Fig. l, thereare centralizing belly springs, not shown, which frictionally engage thewalls of the tubing T and tend to hold the mandrel 10 centered withrespect to the tubing. These belly springs engage the Walls of thetubing with insufficient yfriction to make the 2,950,538 Patented Aug.30, 1960 device self-supporting in the tubing. That is, even though thebelly springs frictionally engage the walls of the tubing and hold themandrel centralized with respect to it they do not prevent the tool fromdescending under its own Weight or being withdrawn from the tubing bythe conductor cable when the conductor cable is elevated.

On the mandrel 10 there is mounted a sleeve or collar 11 that isfastened in position such as by a set screw 12. This collar has aplurality of radially arranged slots 13 formed in the exterior surfacethereof which are defined from each other by what might be regarded asradial ribs 14.

A problem exists in a tool of this character as to how to pivotallymount as large a number of feeler fingers as is possible, it beingdesirable to employ a maximum number of feeler fingers so that as muchof the interior surface of the tubing T will be traversed thereby aspossible. In accordance with the present invention, a groove 15 isformed in the top of the collar so as to traverse the tops of the ribs14. The feeler lingers 16 are positioned in the slots 13 and pivot pins'17, one for each feeler finger, are positioned in the groove 15. Thepivot pins 17 are confined in the groove 15 by means of a cap 18 whichis tightened down against the top of the collar 11 such as by screws 19.The cap is provided with radially extending ribs that are in alignmentwith the ribs 14 and which define therebetween slots that, in effect,form continuations of the slots 13. In this manner, a multiplicity offeeler fingers 16 can be mounted in radial arrangement on the collar 11in close proximity to each other.

The feeler fingers have knobs 20 formed thereon adjacent their lowerends Which engage the interior wall surface of the tubing T. These knobspreferably are hardfaced at their extremities so as to resist wear. Thefeeler fingers are urged outwardly by means of springs 21, the upperportions of which are hooked as at 22 against the backs or inner edgesof the feeler fingers, The other ends of the springs 21 are inserted inaligned apertures 23 in a sleeve 24 that is positioned on the mandrel 10against the underside of the collar 11. These ends of the springs, afterbeing positioned in the aligned apertures, are fastened in position bypeening the metal with a center punch or the equivalent as indicated at25. This construction merely serves to constantly urge the lower ends ofthe feeler fingers outwardly into engagement with the interior of thetubing T.

When a tubing caliper engages a corroded or worn spot on the interior ofa tubing, one or more of the feeler fingers are permitted to swingoutwardly. The magnitude of the movement of the lfeeler finger howeveris quite small and one of the problems involved in the limited spacepermitted in a tubing caliper is to transmit this movement with aminimum amount of effort so that intelligible information can beobtained at the surface as to just 'now far the feeler finger hasexpanded and whether the tubing section being tested has becomedangerously weak.

Above the cap 18 a sleeve 26 is positioned on mandrel 10 and serves tosupport a plate 27 which has radial slots in its outer edge. A sleeve 28rests on the plate and has a radially slotted flange 29 at its bottom inwhich there is formed a groove 30. The groove 30 receives a split ring31 which serves in turn to pivotally support a plurality of bellcranksor levers 32. rThe ring 31 is confined in the groove 3! by the plate 27.The lower ends of the bellcranks 32 are disposed closely adjacent theupper ends of the feeler fingers and are adjustably engaged thereby, theadjustment being provided by bolts 33 which are threaded through thetops of the feeler fingers and which actually engage the bellcranlcs.These bolts when adjusted are locked in adjusted position such as by jamnuts- 34. The tops of the bellcranks extend outwardly and downwardly toengage the downwardly and inwardly inclined surface 35 on an internalflange formed at the bottom of a skirt 36 that surrounds the mandrel.The skirt has a hub portion 37 which is slidable upon the sleeve 28. Itis constantly urged upwardly by tension springs 38 anchored at theirupper ends on bolts 39 and at their lower ends in studs 40 that arethreaded into the top of the skirt so that adjustment of the tensionexerted by the springs can be accomplished. On the top of the skirt 36there is a stud 41 to which is threaded a collar I42. A push rod 43 isfastened in the top of the collar 42 such as by a set screw 44. Thispush rod serves to vertically move a contact member generally indicatedat 45. The contact member 45 has a plurality of contacts thereon,indicated respectively by the reference characters 46, 47, 48, 49, and Swhich are separated from each other by insulation 51. These contacts areelectrically connected to each other and to ground as illustrated inFig. 6. Adjacent the contact member, blocks of insulation 52 are mountedon the skirt and contacts in the form of screws 53 are mounted on thearms 54 of pivotally mounted contact supports. The contact supports arepivoted for swinging movement about pivots 55 and are continually urgedtoward the contact member 45 by leaf springs 56. They are so arrangedwith respect to the contacts 46, `47, 43, 49, and 50 as to sequentiallyengage their respective contacts when the contact member is movedvertically. Thus, as illustrated in Fig. 2A, the lowermost contact screw53 is barely in engagement with its contact 46. The next contact screw53 has not engaged but is almost in engagement with its contact 47. Thethird contact screw 53 is spaced a greater distance from its contact 48.Similarly, the fourth contact screw 53 is spaced somewhat farther fromits contact 49' and the uppermost contact screw 53 is spacedconsiderably from its contact 50. If the contactor 45 is moveddownwardly the second contact screw 53 will be brought into contact withits contact 47 and subsequently the third contact screw will be boughtinto contact with its contact 48. Thereafter, the upper contact screwswill be brought into contact with their contacts 49 and 50 in sequence.

It will be noted that the contact screws 53 are longitudinallyadjustable with respect to the arms 54 merely by rotating and screwingthe contact screws in their respective arms. As the arms 54 swing aboutthe axes of pivots 55 which are normal or at right angles to the axis ofthe contact member 45 a considerable adjustment or screwing of thescrews 53 is possible before the adjustment causes any appreciablechange in the vertical position of its contacting end with respect tothe dividing line between its contact of the contact member and theinsulation 51 thereon. This arrangement makes a very tine adjustmentpossible in that if it is found that the contacting end of the contactscrew 53 should be raised or lowered slightly to perserve the desiredsequence of operation a considerable screwing of the contact screw canbe done to perform this adjustment and the vertical change in positionis Very small. Consequently, the parts can be very accurately adjustedto have the proper sequence of operation brought about by the outwardswinging movement or expansion of a feeler linger 16.

The lowermost contact screw 53 has a resistor 57 in series therewith,and is connected to the next contact screw and to a resistor 58associated therewith. This resistor, in turn, is connected to the thirdcontact screw 53 and to the resistor 59 associated therewith which, inturn, is connected to the fourth contact screw and the resistor 60associated therewith. The fourth contact screw is connected to theuppermost contact screw 53 and to the conductor cable, not shown, which,in turn, is connected to a source of current represented by battery 61and to a metervor recording device indicated at 62 which, in turn, isgrounded as indicated at 63.

In testing tubing the apparatus as above described is 4 caused tovertically pass through the tube. When a pit or depression indicated 'atP on Fig. 3B is encountered by one or more of the feeler lingers 16,these feeler fingers will be urged outwardly by means of their springs21. When the feeler fingers are swung outwardly the adjusting theadjusting screws 33 thereon force the lower ends of their bellcranks 32inwardly causing the outer ends of the bellcranks to move downwardly onthe inclined surface 35 and in effect cam the skirt 36 downwardlyagainst the sult that the meter reading is the maximum.

action of the tension springs 38. The relationship of the be'llcranks tothe inclined surface is such that a very small amount of outwardswinging movement of the feeler lingers 16 is translated into verticalmovement of the skirt which, in turn, moves the contact member 45downwardly. The extent of downward movement of the contact member isdependent upon the extent of outward swinging movement of one or morefeeler lingers 16. If theoutward swinging movement is relatively smallit may be that only the lower contacts 46 and 47 will be engaged bytheir respective contact screws 53. If this is the case, current fromthe source of supply 61 is required to pass through both resistors 59and 60 before reaching ground. Consequently, a relatively small readingwill be obtained upon the meter or recorder 62. On the other hand, ifthe outward wsinging movement of the feeler linger 16 is of considerablemagnitude the downward movement of the contact member 45 will begreater, and if contacts 46, 47, 48, and 49 are all engaged by theircontact screws 53, the current need only pass through resistor 60 beforereaching ground, and the reading on the meter will be correspondinglygreater. When the uppermost contact 50 is engaged by its contact screw adirect current through the contact member'to ground is provided with there- In this manner, even though the space available in the caliper isvery small, live different depths to which the feeler lingers 16 may beexpanded can be accurately determined. Additional contacts may bearranged on the contact memberl 45 andv additional contact screws can beassociated with them respectively if desired.

In some instances, the apparatus above described, canVVV be run in twosections which are duplicates of eac'h other and which are run in tandembetween the belly springs. If this is the case, the feeler lingersY ofone section are preferably oriented or arranged in straddlingrelationship to the feeler ngers of the other section. In this manner,

the entire inside surface of the tubing can be calibrated.

It will be appreciated from the above-described construction that theyfeeler fingers and their bellcranks can be easily and ellicientlymounted for pivotal or swinging movement on the central supportingstructure, and that small movements of the feeler lingers can betranslatedv into movements of the contact member 45. Furthermore, thedegree of extent of movement of the contact member can be accuratelyascertained by the number of resistances 57 to 60, inclusive, that arecut in or shunted.

out of the electric circuit.

Various changes may be made in the details of construction withoutdeparting from the spirit and scope of the invention as deiined by theappended claims, wherein:A

I claim: A tubing caliper comprising a central supporting structure, aplurality of feeler fingers swingably mounted uponY when any feelerlinger is allowed to swing outwardly its bellcrank will cause the skirtto move axially, and'means4 5 6 for indicating the distance that theskirt has moved in 1,089,564 Hull Mar. 10, 1914 response to a feelerl'inger swinging outwardly. 2,630,632 Brandon Mar. 10, 1953 2,638,681Knley et a1 May 19, 1953 References Cited in the file of this patent2,766,533 Brandon Oct 16, 1956 UNITED STATES PATENTS 5 2,775,820 WorthenIan. 1, 1957 960,450 Van Valkenburg June 7, 1910

